ES2364417T3 - SYSTEMS FOR THE LIMITATION OF SPINE APOPHYSIS WITH CLAMPS. - Google Patents

Abstract

Spinal implant (30) comprising: at least two complementary elements (34), each complementary element having an upper end and a lower end; an upper clamping segment (32) extending between the upper ends of the two complementary elements (34), said upper clamping segment (32) being adapted for placement on a spinous process or a first vertebra; a first lower clamping segment (36) attached to an upper end, to a first of the complementary elements (34) and having a lower end adapted to be fixedly attached to a vertebra or sacrum adjacent to the first vertebra; and a second lower clamping segment (38) attached to an upper end than a second of the complementary elements (34) and having a lower end adapted to be fixedly attached to the vertebra or sacrum adjacent to the first vertebra

Description

BACKGROUND OF THE INVENTION

[0001] Field of the invention. The present invention relates generally to medical devices. More particularly, the present invention relates to devices for limiting flexion of the spine in patients with back pain or other spinal pathologies.

[0002] An important source of chronic low back pain is discogenic pain, also known as internal disc disruption. Patients suffering from discogenic pain tend to be young, healthy in the rest, who have localized back pain. Discogenic pain usually occurs in the discs located at the L4-L5 or L5-S1 junctions of the spine (Figure 1). The pain tends to be exacerbated when patients put their lower back in flexion (that is, when sitting or leaning forward) and it is relieved when they put their lower backs in extension (ie, arched backwards). Discogenic pain can be very disabling, and for some patients, they can dramatically affect their ability to work and enjoy their lives.

[0003] This pain experienced by patients with discogenic low back pain can be considered as flexion instability, and is related to flexion instability manifested in other conditions. The most frequent of these is spondylolisthesis, a pathology of the spine in which it is an abnormal segmental translation is exacerbated by segmental flexion. The device described herein as such should also be useful for these other spine disorders associated with segmental flexion, for which either prevention or control of segmental flexion of the spine is desired.

[0004] Current treatment alternatives for patients diagnosed with chronic discogenic pain are quite limited. Many patients follow conservative treatment, such as physiotherapy, massage, anti-inflammatory and analgesic medications, muscle relaxants, and epidural steroid injections, but usually continue to suffer a significant degree of pain. Other patients choose to undergo spinal fusion surgery, which usually requires discectomy (disc removal), along with the fusion of adjacent vertebrae. Fusion is not generally recommended for discogenic pain because it is irreversible and expensive, it is associated with high morbidity and questionable efficacy. Despite its drawbacks, however, spinal fusion for discogenic pain remains common due to the lack of viable alternatives.

[0005] Recently, a less invasive and potentially more effective treatment for discogenic pain has been proposed. A spinal implant that inhibits spinal flexion has been designed, while allowing spinal extension to be substantially unrestricted. The implant is placed on one or more adjacent pairs of spinal processes and provides an elastic limitation to the extension with respect to the spine processes that occur during flexion. Such devices and procedures for use are described in US patent application 2005 / 0216017A1, published on September 29, 2005, and which has inventors in common with the present application.

[0006] As illustrated in Figure 2, an implant 10 as described in application 017 typically comprises an upper belt component 12 and a lower belt component 14 connected by a pair of compatible elements 16. The belt upper 12 is shown disposed on the upper part of the spinous process SP4 of L4, while the lower belt 14 is shown extending over the lower part of the spinous process SP5 of L5. The compatible element 16 typically includes an internal element, such as a rubber or elastic block, which is fixed to the belts 12 and 14 such that the belts can be "elastically" or "compatible" when the spinal processes SP4 and SP5 They separate during flexion. In this way, the implant provides an elastic tension in the spinal processes, which provides a force that resists flexion. The force increases, typically linearly with a non-variable elastic constant, when the processes are further separated. Usually, the straps themselves will be essentially non-compatible, so that the degree of elasticity or compatibility can only be controlled and supplied by the compatible elements 16.

[0007] Despite offering important benefits, the system illustrated in Figure 2 can be difficult to implant in certain patient anatomies if the spinal processes are relatively small or have certain geometries. In addition, the systems are not intended for implantation in the LS-S1 junction, since the spinous process in the sacrum is not always sufficient for fixation with this system.

[0008] For these reasons, it would be desirable to provide improved spinal implants for inhibition of flexion in patients suffering from discogenic pain. It would be particularly desirable if the improved implants were suitable for implantation at the L5-S1 junction and in patients who have anatomies that present other difficulties for the implantation of the previous systems as described in application ‘017. At least some of these objectives will be achieved through the inventions described below.

[0009] Description of the prior art. US 2005 / 0216017A1 has been described above. Other patents and published applications of interest include: US Patents 4,966,600, 5,011,494, 5,092,866, 5,116,340, 5,282,863, 5,395,374, 5,415,658, 5,415,661, 3,449,361, 5,456,722 , 5,462,542, 5,496,318, 5,540,698, 5,609,634, 5,645,599, 5,725,582, 5,902,305, Re. 36221, 5,928,232, 5,935,133; 5,964,769; 5,989,256, 6,053,921, 6,312,431, 6,364,883, 6,378,289, 6,391,030, 6,468,309, 6,436,099, 6,451,019, 6,582,433, 6,605,091, 6,626,944, 6,629. 975,

6,652,527, 6,652,585, 6,656,185, 6,669,729, 6,682,533, 6,689,140, 6,712,819, 6,689,169; 6695852, 6716245, 6761720, 6835205; Published patent application US 2002/0151978, US 2004/0024458, US 2004/0106995, US 2004/0116927, US 2004/0117017; US 2004/0127989, US 2004/0172132, US 2005/0033435, US 2005/0049708, US 2006/0069447; PCT application published WO 01/28442 A1; WO 02/03882 A2; WO 02/051326 A1; WO 02/071960 A1; WO 03/045262 A1; WO 2004/052246 A1; WO 2004/073532 A1, and published foreign application EP 0322334 A1, and FR 2 681 525 A1.

[0010] Document FR 2 851 154 describes an interspinal device to obstruct the movement of two successive vertebrae of the spine. The device includes two pads whose internal faces are intended to be pressed against the lateral faces of the spinal processes of the vertebrae and the ligaments that connect the pads with each other and with the spinal processes so that, during the flexion and extension movements of the spine with respect to its normal position, the pressure exerted against the lateral faces of the spinal processes by means of the pads increases when the spine moves away from the normal position.

[0011] US 2005/216017 describes a spinal implant system to limit spinal flexion that includes an elongated band provided to engage with at least two spinal processes. During use, the band is placed coupled with the spinal processes in a segment of the spine of interest, where flexion in the segment is restricted. The length and tension of the band can be adjustable using after implantation using transcutaneous or percutaneous means.

BRIEF DESCRIPTION OF THE INVENTION

[0012] The present invention provides spinal implants as indicated in the appended claims, to limit flexion of the spine for the treatment of discogenic pain and other spinal pathologies, such as spondylolisthesis, in which the physician can want to control segmental flexion. The implants of the present invention are particularly useful for the treatment of the L4-L5 and L5-S1 junctions of the spine (Figure 1). The first segment of the fastening structure is generally a loop similar or identical to the belt 12 in Figure 1, which is not fixedly attached to a spinous process, typically being placed on a superior spinous process, but not fixed on another way to the spinous process. Thus, the first segment of the belt will be able to move to move laterally and / or in the anterior-posterior direction in relation to the spinous process when the spine is subjected to flexion and extension.

[0013] The lower segments of the belt are adapted to be fixedly attached to the adjacent vertebrae or sacrum in a variety of ways. For example, the lower segments of the belt structure can be fixedly attached to the vertebra or sacrum, for example with screws, pegs, staples, pins, suture thread, or the like. When attached to a vertebra, the two separate end segments can be joined to opposite sides of a spinous process of a lower vertebra. When attached to a sacrum, the two separate end segments can be attached to an alar surface of the sacrum, typically with wing screws.

[0014] In all cases, the belt structure will typically provide little or no restriction or resistance to spinal extension. Very often, the belt structure will be free of components or other structures that are located between the adjacent spinal processes or between the spinal processes and the adjacent sacrum. In other cases, however, a transverse element or other low profile structure can be placed between the two compatible elements to maintain the union of the compatible elements, generally as described in the application filed at the same time No. 11 / 777,366, presented the same day as the present application and now published as US 2008-017726. The use of transverse elements for the stabilization of compatible elements can be advantageous when the lower portion of the belt structure is not fixedly attached to the lower or sacral vertebra.

[0015] The lower ends of the first and second lower clamping segments with typically non-compatible straps and can be adapted to be screwed into adjacent vertebrae or sacrum. Alternatively, the lower ends of the first and second lower clamping segments can be adapted to connect to a pin implanted in the adjacent or sacral vertebra. The spinal implant can optionally be attached to screws, anchors, or other fasteners to be fixedly attached to the lower ends of the clamping segments to the vertebra or sacrum.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016]

Figure 1 is a schematic diagram illustrating the lumbar region of the spine that includes spinal processes (SP), joints (FJ), lamina (L), transverse processes (TP), and sacrum (S).

Figure 2 illustrates a spinal implant of the type described in US 2005 / 0216017A1.

Figure 3 illustrates a first example of a spinal implant adapted to be placed between a pair of spinal processes and having a lower clamping segment attached in a manner not fixed to the inferior spinous process.

Figure 4 is a first embodiment of a spinal implant adapted to be placed between adjacent spinal processes and having a lower segment adapted to be fixedly attached to the inferior spinous process.

Figure 5 illustrates a second example of a spinal implant having an upper end placed on the spinous process of L5 and a lower end held in a manner not fixed to the sacrum.

Figure 6 illustrates a second embodiment of a spinal implant according to the present invention having an upper end fixed on a spinous process of L5 and two separate lower segments fixed to a bolt implanted in the sacrum.

Figure 7 illustrates a third embodiment of a spinal implant according to the present invention having an upper segment placed on a spinous process of L5 and two separate lower segments fixedly fixed with wing screws to the sacrum.

Figure 8 illustrates a fourth embodiment of a spinal implant according to the present invention having an upper segment placed on a spinous process of L5 and two separate lower segments fixedly joined by screws of articular face superior to the sacrum.

Figure 9 illustrates a fifth embodiment of a spinal implant according to the present invention having an upper segment placed on a spinous process of L5 and two separate lower clamping segments, each of which passes through a hole created in the upper articular face of S1 and is held in a non-fixed manner through a lever anchor (anchor t).

Figure 10 illustrates a sixth embodiment of a spinal implant according to the present invention having an upper segment placed on a spinous process of L5 and two separate lower clamping segments, each of which is connected to a hook attached to the foramen. dorsal S1.

DETAILED DESCRIPTION OF THE INVENTION

[0017] With reference now to Fig. 3, an example spinal implant 20 comprises an upper belt 22, a lower band 24, and a pair of complementary elements 26 joining the upper and lower belts. Typically, the upper and lower belts 22 and 24 will be non-distensible, but will be attached to the complementary elements 26, so that it can be expanded from a restricted configuration, as shown in dashed lines, when the patient's spine is it is in a neutral position between flexion and extension, to an expanded configuration (shown in a continuous line) when the patient's spine is flexed. The complementary elements 26 will provide a force that acts against the extension of the spinal processes SP4 and SP5, as generally described in the previous patent application US 2005/0216017.

[0018] In contrast to the teachings of application ‘017, however, the lower belt 24 is not fixedly attached to the spiny process SP5 of L5. When passing through an orifice H formed in the spinous process SP5, the lower belt 24 is held stably and will not move.

[0019] With reference now to Figure 4, a spinal implant 30 may comprise a clamping structure that includes an upper belt 32, a pair of compatible elements 34, and the first and second lower belts 36 and 38, a belt that is extends from each of the compatible elements 34. The lower belts 36 will typically be unsupported, as will the upper belt 32, with the compatibility and elasticity provided by 34 compatible elements. The lower ends of the lower belts 36 and 38 can be fixedly attached to the spinous process SP5 with screws 40 or any suitable anchor. Using the screw or other anchors, the lower belts 36 and 38 can be fixedly attached to the spinous process SP5, not allowing relative movement between the belts 36 and 38 and the spinous process SP5 and L5. The upper belt 32, on the other hand, will be able to move or change slightly in relation to the upper spinous process SP4 in L4, although the interspinous ligament that extends between L4 and L5 (through which the belt passes) will resist movement in the front part - back direction.

[0020] Referring now to Figure 5, the example implant 20, which is generally described in Figure 3, can also be implanted between the spinous process SP5 of L5 and the sacrum S. The upper belt 22 is placed on the spinous process SP5 while the lower belt 24 is placed through a hole H placed in a surface rib on the dorsal surface of the sacrum.

[0021] Referring now to Figure 6, a spinal implant 40 comprising an upper belt 42, a pair of compatible elements 44 and lower clamping segments 46 and 48 may be implanted in the spinous process SP5 of L5 and the sacrum S In particular, a bolt or any other element can be implanted in the spinous process S1 of the sacrum (which is usually small in relation to the spinous process of L5 and less capable of providing an anchor around which a belt can be placed) and Rings 50 and 52 at the lower ends of the lower clamping segments 46 and 48 can be placed on the bolt or other anchor.

[0022] As illustrated in Figure 7, another alternative for implant implantation 60 is illustrated. Implant 60 comprises an upper belt 62, a pair of compatible elements 64 and lower clamping segments 66 and

68. The upper clamping segment is placed on the spinous process SP5 of L5, while the lower band segments 66 and 68 are anchored in the alar region of the sacrum by means of wing screws 70.

[0023] As illustrated in Figure 8, an additional alternative for the implantation of a

5 implant 60. The implant 60 comprises an upper belt 62, a pair of compatible elements 64 and lower clamping segments 66 and 68. The upper clamping segment is placed on the spinous process SP5 of L5, while the lower clamping segments 66 and 68 are anchored on upper articular faces of the sacrum by means of upper articular face screws 72.

[0024] As illustrated in Figure 9, another alternative for implanting an implant 80 is illustrated.

10 implant 80 comprises an upper belt 82, a pair of compatible elements 84 and lower clamping segments 86 and 88. The upper clamping segment is placed on the spinous process SP5 of L5, while the lower clamping segments 86 and 88 pass through the dorsal-medial to proximal-lateral through holes 90 created on the upper articular face of S1 and are fixedly attached through lever anchors (anchors t) 92 on the lateral-proximal side of the faces.

[0025] As illustrated in Figure 10, an additional alternative for implanting an implant 100 is illustrated. The implant 100 comprises an upper belt 102, a pair of compatible elements 104 and lower clamping segments 106 and 108. The upper clamping segment is placed on the spinous process SP5 of L5, while the lower clamping segments 106 and 108 are connected to hooks 110 attached to the dorsal foramen F S1.

[0026] Although the above is a complete description of the preferred embodiments of the invention, various alternatives, modifications, and equivalents can be used. Therefore, the above description should not be taken as a limitation of the scope of the invention, which is defined in the appended claims.

Claims (6)

1. Spinal implant (30) comprising: at least two complementary elements (34), each complementary element having an upper end and a lower end; an upper clamping segment (32) extending between the upper ends of the two complementary elements (34), said upper clamping segment (32) being adapted for placement on a spinous process or a first vertebra; a first lower clamping segment (36) attached to an upper end, to a first of the complementary elements (34) and having a lower end adapted to be fixedly attached to a vertebra or sacrum adjacent to the first vertebra; Y a second lower clamping segment (38) attached to an upper end to a second of the complementary elements (34) and having a lower end adapted to be fixedly attached to the vertebra or sacrum adjacent to the first vertebra.

2.

 Spinal implant according to claim 1, wherein the lower ends of the first and second lower clamping segments (36, 38) are adapted to be screwed into the adjacent vertebra or the sacrum.

3.

 Spinal implant according to claim 1, wherein the lower ends of the first and second lower clamping segments (36, 38) are adapted to be connected to a bolt implanted in the adjacent vertebra or the sacrum.

Four.

 Spinal implant according to claim 1, which also comprises wing screws (70) for joining said lower ends to a sacrum.

5.

 Spinal implant according to claim 1, which also comprises upper articular face screws (72) for joining said lower ends to a sacrum.

6.

 Spinal implant according to claim 1, wherein the lower ends of the first and second lower clamping segments (36, 38) are adapted to pass through dorsal-medial to proximal-lateral holes created in the upper articular faces and fixed in the holes through anchors on the lateral-proximal side of the faces.